U.S. Pat. No. 6,460,686, discloses a machine that inspects glass bottles. This machine is an indexing, starwheel type machine. Containers enter a starwheel by use of a timing feed screw. This feed screw releases containers in time with starwheel displacement such that each container enters an open pocket. The starwheel then indexes rotationally a fixed amount and stops or dwells. Various forms of inspection take place at each dwell position. The starwheel continues the index and dwell cycle. After the last dwell station, the container is removed from the starwheel with guides on opposing sides of the container. The outside guide is fixed and the inside guide is a moving guide (the end portion of a belt conveyor), which provides a motive force that drives the container out of the starwheel and into the transfer mechanism.
With this methodology, the container rolls along the fixed guide. It is driven by the moving guide. The forward velocity of this container along the fixed guide can be shown to be equal to one half the linear velocity of the moving guide. The transfer mechanism consists of the above discussed belt conveyor and a second conveyor operatively associated with a forward portion of the first belt conveyor. These belt conveyors travel at identical velocities. Once the container reaches the end of the fixed guide, it contacts the second belt conveyor which with the first belt conveyor, causes the container to double its velocity, to match the speed of the belt conveyors.
The first belt conveyor must be moving fast enough to prevent two adjacent containers from coming into contact. Once the containers reach the second belt conveyor, the spacing doubles due to the doubling of their forward velocity. The drawback to this method is that the containers are traveling at a high velocity as they exit the machine. This high velocity must be transferred to the downstream conveyors, as it is desirable to closely match conveyor speeds for container stability. If this speed could be reduced, it would improve downstream stability, thus reducing the falling over of containers and resulting stoppages.